How do Swedish tweens (10–14 years old) understand and experience the writing of their online identities? How are such intertwined identity markers as gender and age expressed and negotiated? To find some answers to these questions, participants in this study were asked to write a story about the use of online web communities on pre-prepared paper roundels with buzzwords in the margins to inspire them. Content analysis of these texts using the constant comparative method showed that the main factors determining how online communities are understood and used are the cultural age and gender of the user. Both girls and boys chat online, but girls more often create blogs while boys more often play games. Gender was increasingly emphasised with age; but whereas boys aged 14 described themselves as sexually active and even users of pornography, girls of the same age described themselves as shocked and repelled by pornography and fearful of sexual threats. In this investigation an intersectionalist frame of reference is used to elucidate the intertwined power differentials and identity markers of the users' peer group situation.